首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3370571篇
  免费   247692篇
  国内免费   8587篇
耳鼻咽喉   46675篇
儿科学   113542篇
妇产科学   93538篇
基础医学   474123篇
口腔科学   92748篇
临床医学   305525篇
内科学   662642篇
皮肤病学   79110篇
神经病学   273638篇
特种医学   130732篇
外国民族医学   1282篇
外科学   507854篇
综合类   70302篇
现状与发展   6篇
一般理论   1230篇
预防医学   258061篇
眼科学   76774篇
药学   248700篇
  9篇
中国医学   6851篇
肿瘤学   183508篇
  2019年   26215篇
  2018年   37100篇
  2017年   28367篇
  2016年   32673篇
  2015年   36685篇
  2014年   50713篇
  2013年   76345篇
  2012年   102192篇
  2011年   108322篇
  2010年   65264篇
  2009年   62293篇
  2008年   101421篇
  2007年   107947篇
  2006年   109384篇
  2005年   105241篇
  2004年   101793篇
  2003年   98271篇
  2002年   95123篇
  2001年   161567篇
  2000年   166026篇
  1999年   140473篇
  1998年   40344篇
  1997年   35878篇
  1996年   36068篇
  1995年   34758篇
  1994年   32212篇
  1993年   30203篇
  1992年   110247篇
  1991年   106541篇
  1990年   103432篇
  1989年   99900篇
  1988年   91674篇
  1987年   89951篇
  1986年   84151篇
  1985年   80422篇
  1984年   60137篇
  1983年   50927篇
  1982年   29956篇
  1981年   27042篇
  1979年   53451篇
  1978年   37562篇
  1977年   32041篇
  1976年   29708篇
  1975年   31764篇
  1974年   37389篇
  1973年   35639篇
  1972年   33327篇
  1971年   30715篇
  1970年   28628篇
  1969年   26971篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
3.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
4.
5.
6.
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered.  相似文献   
7.
8.
9.
Treatment guidelines for management of uncomplicated gonorrhoeae have been recently modified owing to alarming upsurge in azithromycin resistance. This study investigated the prevalence and genetic determinants of gonococcal azithromycin resistance in India. Four (5.7%) of 70 gonococcal isolates were resistant to azithromycin. Of 16 isolates investigated for molecular mechanisms of resistance, 13 (81.3%) and 6 (37.5%) isolates exhibited mutations in coding and promoter regions of mtrR gene, respectively. However, ermA, ermB and ermC genes or mutations in rrl gene were absent in all isolates. Azithromycin resistance is low in India posing no immediate threat to use of dual-therapy for syndromic management.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号